In a typical cellular network, also referred to as a communication network, User Equipments (UEs), communicate via a Radio Access Network (RAN) to one or more Core Networks (CN).
A user equipment is a mobile terminal by which a subscriber may access services offered by an operator's core network and services outside the operator's network to which the operator's RAN and CN provide access. The user equipments may be for example communication devices such as mobile telephones, cellular telephones, or laptops with wireless capability. The user equipments may be portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another mobile station or a server.
User equipments are enabled to communicate wirelessly in the cellular network. The communication may be performed e.g. between two user equipments, between the user equipment and a regular telephone and/or between the user equipment and a server via the radio access network and possibly one or more core networks, comprised within the network.
The cellular network covers a geographical area which is divided into cell areas. Each cell area is served by a base station, e.g. a Radio Base Station (RBS), which sometimes may be referred to as e.g. evolved Node B (eNB), “eNodeB”, “NodeB”, “B node”, or Base Transceiver Station (BTS), depending on the technology and terminology used. The base stations communicate over the air interface operating on radio frequencies with the user equipments within range of the base stations.
In telecommunications, the term interference may be defined as anything which alters, modifies, or disrupts a signal as it travels along a channel between a source and a receiver, e.g. between a base station and a user equipment. The term typically refers to the addition of unwanted signals to a useful signal. For example, interference may cause voice quality to drop, call drop, link and network performance degradation etc. However, it is possible to cancel the interference. Interference cancelling comprises removal of an undesired component from a signal, which signal comprises both a desired signal and an undesired signal.
In a near future, Interference Cancelling (IC) capable user equipments are a reality. Using IC other data streams/users and/or arbitrary signals may be estimated and subtracted from the desired data stream and thereby significantly improve the link performance for user equipments that experience significant inter/intra-cell interference. Apart from the common homogeneous network layouts, such advanced receiver features of the user equipments will become especially important in heterogeneous network deployments that are currently standardized.
Interference cancelling typically comprises multiple coding and decoding steps, which significantly increase the total processing cost and hence increases a user equipments power consumption. While there are scenarios where these techniques are necessary to maintain good link performance, there are also scenarios where this kind of processing is not needed, for example when there is actually no intra/inter-cell interference at all and in this case, IC might even degrade the performance, or even when the UE is within an area or cell where previous measurements and other previous knowledge of the network has shown that interference in this area originates only from 1 or 2 neighbor cells. In such a case, other techniques such as fractional frequency reuse, fractional power control may reduce other cell interference only by actions taken by the network. Thereby always using IC in a battery driven user equipment is an unnecessary use of the processing resources and battery power.